December 5, 2019

It's almost december and that means it's finals time! This can be very overwhelming and stressful. At Transformation Tutoring, we came up with tips on how to best prepare for your chemistry finals.

1. Make a to-do list. List items in terms of priority. Since time is limited, it is important to focus on the most important tasks that need to be done.  Make a big plan for the two upcoming weeks with major milestones (for ex...

November 17, 2019

What is the chemical name of the compound NH4SCN?

(1) ammonium thiocyanate

(2) ammonium cyanide
(3) nitrogen hydrogen cyanide

(4) nitrogen hydrogen sulfate

Answer: (1) ammonium thiocyanate

Explanation: In order to name a compound, we must first figure out whether it is ionic or covalent. Ionic compounds can be divided into three categories: metal + nonmetal, meta+ polyatomic ion, polyatomic ion+ polyatomic ion, polyatomic io...

October 23, 2019

To convert grams to moles and vice versa, we must always use Molar Mass.

Molar Mass can be calculated using the Periodic Table.

To calculate the molar mass, we multiply each atom in the molecule by its atomic mass found in the Periodic Table and multiply by the number of atoms.

For example, to calculate the molar mass of CO2

C= 1*12.011 = 12.011

O= 2*15.999 = 31.998

12.011 + 31.998 = 44.009 g/mol

To convert grams to moles, we...

October 16, 2019

Will precipitation occur when the following solutions are mixed? If so, write a balanced chemical equation for the reaction.

(a) Na2CO3 and AgNO3, (b) NaNO3 and NiSO4, (c) FeSO4 and Pb(NO3) 2

In order for precipitation occur, we must first write out the products of each reaction. These are double replacement reactions, where we can use the following formula: AB+CD --> AD + CB to predict the products. We also need to remem...

October 8, 2019

Which notations represent atoms that have the same number of protons but a different number of neutrons?

                                               

(1) H-3 and He-3

(2) S-32 and S-32

(3) Cl-3...

September 30, 2019

A sample of the male sex hormone testosterone,C19H28O2, contains 3.88 * 10^21 hydrogen atoms.

(a) How many atoms of carbon does it contain?

(b) How many molecules of testosterone does it contain?

(c) How many moles of testosterone does it contain?

(d) What is the mass of this sample in grams?

Answer: 

To find atoms of carbon, we take the number of hydrogen atoms and multiply the number by 19/28 (ratio of carbon to hydrogen...

September 25, 2019

How To Name Acids 

An acid is a substance that releases H+ ions (hydrogen ions) when it is dissolved in water.

Acids can be divided into 2 categories: binary acids and oxyacids.

Binary Acid - consists of H + nonmetal

Examples of binary acids are HCl, H2S, HBr

Naming a binary acid - HYDRO _____ IC ACID

HCl - hydrochloric acid

H2S - hydrosulfuric acid

Oxoacid - consists of H + Polyatomic ion containing O

Examples of oxoacids are H...

September 23, 2019

How to convert moles into mass?

To convert moles into mass, we first need to find the molar mass of the compound given. This can be done by looking at the mass of each element in the periodic table and then multiplying each mass by the number of atoms of that element in the compound. Molar mass has the units grams/mol which allows to convert between moles and grams.

To go from moles to grams, we need to multiply the numbe...

September 17, 2019

January 2019 Chemistry Regent

During which phase change does the entropy of a sample of H2O increase?

(1) H2O(g) → H2O(l)

(2) H2O(g) → H2O(s)

(3) H2O(l) → H2O(g)

(4) H2O(l) → H2O(s)

Answer and Explanation:

Entropy represents disorder in chemistry. Universe wants to be as disordered as possible and therefore increasing disorder, or entropy, is favorable. Now, lets lookout phases to figure out what is more d...

September 14, 2019

There is a simple and easy way to identify ionic  versus compounds.

Ionic compounds can be of three types:

1. Metal + Nonmetal

To figure out whether an element is a metal or a nonmetal, look at the periodic table. Elements on the right of the staircase on the periodic table are metals. Elements to the left of the staircase on the periodic table are nonmetals. Hydrogen is a nonmetal even though it is located on the rig...

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